The present invention is directed to the printer head art, and, more particularly, to a wire matrix printer head employing piezoelectric drivers.
Printer heads of the wire matrix type are well known in the art, especially as used in computer or other machine activated printing devices. Conventional wire matrix print heads comprise a plurality of solenoids, each of which drives a particular wire in the wire matrix. In response to signals from the control machinery, selected wires in the matrix drive carbon paper against the printout paper, thereby leaving an identifying mark. The machine may produce either a coded printout, or conventional alphanumeric characters.
Due to the poor energy conversion efficiency of the magnetic solenoids, they have suffered numerous problems in application. To achieve the high accelerating forces necessary for rapid printouts, high currents must be passed through the solenoids which, therefore, must dissipate up to twenty watts of electrical power. This often results in overheating of the solenoids or, in the alternative, restricting the printing speeds to increase solenoid life. As a further alternative the solenoids may be made larger and heavier, thereby increasing cost, printer head size and weight.
A highly efficient transducer is the piezoelectric bimorph bender. However, until my recent invention, U.S. Pat. application Ser. No. 644,665, filed Dec. 24, 1975 and assigned to the same assignee as the instant application, such benders were not capable of the high accelerating forces required in printer head applications. Due to my development, however, the high power bimorph bender has become suited for high force, high acceleration applications.